1. Field of the Invention
The present invention relates generally to providing targeted disaster warnings to telephone subscribers in pre-determined geographic areas.
2. Background of the Invention
Early warnings of natural (e.g., tornadoes) or man-made (e.g., leaks of toxic gases) disasters can save lives. However, any warning, no matter how timely, must be actually received by the people in danger, and must be heeded by the recipient if there is to be any benefit. Conventional systems for issuing disaster warnings may be directed to very large populations, for example, by radio or television, or may be directed to very small populations, for example, by people going house-to-house to notify the occupants. More recently, xe2x80x9cweather radioxe2x80x9d is being implemented to allow more localized warnings based on the listener""s specific location.
However, all of these early warning systems have inherent disadvantages that reduce their effectiveness. For example, in the case of radio and television broadcasts, the television or radio sets must be turned on and monitored for the warning to be received. Moreover, it is not uncommon for the power systems in disaster zones to be out of operation, further limiting the likelihood that the target audience will receive the warnings. Finally, because television is designed to reach a maximum audience in a geographic region, it cannot currently be used to specifically target only those in the greatest danger. Thus, the warnings are sent to far more people than actually need to be warned. If people are often interrupted by alarms that do not apply to them, then they are less likely to heed subsequent warnings.
The xe2x80x9cweather radioxe2x80x9d system, when fully implemented, may overcome some of these limitations by issuing a radio signal to specially purchased radio receivers. The signal will cause the radio set to turn itself on and broadcast the warning to all listeners. However, even this solution has some disadvantages. First, the system is not in widespread use because it requires the purchase of a special radio receiver. Second, while weather radio can be directed toward a more specific geographic area than other broadcasting means, it cannot target very small regions, such as people located on a certain street. More people will receive the warning than are actually in danger, resulting in false alarms for many people. Thus, with weather radio systems, the result could be even more dangerous, as people who have been inconvenienced by false alarms may disable the feature or merely ignore further weather radio warnings.
When house-to-house personal warnings are issued, or neighborhood-wide announcements made via loud speakers, the deficiency is not in reaching the correct audience, but reaching them in time to provide sufficient early warning. Even if the target area is very small, if the danger stems from a rapidly moving force, such as a tornado, personal notification cannot provide the necessary early warning.
The present invention utilizes an Advanced Intelligent Network (xe2x80x9cAINxe2x80x9d) to provide early disaster warnings to recipients in specifically targeted geographic areas. AIN systems are described in U.S. Pat. No. 5,701,301 and U.S. Pat. No. 5,774,533, which are incorporated herein by reference in their entirety. The invention uses existing calling number delivery (xe2x80x9cCNDxe2x80x9d) and calling name delivery (xe2x80x9cCNAMxe2x80x9d) systems to provide early disaster warnings to subscribers within the targeted areas. The invention includes a specialized service node (xe2x80x9cS-SNxe2x80x9d) shown in the FIG. 1. The S-SN is connected to a computer control terminal that defines the geographic area to which the targeted warning message must be sent. The S-SN is a service node, as is currently well known in the art, with added capabilities such as multiple communications links to multiple service switching points (xe2x80x9cSSPsxe2x80x9d or xe2x80x9cswitchesxe2x80x9d). Additionally, the S-SN is programmed to partially emulate an SSP by issuing call setup and release messages to other SSPs using the Common Channel Signaling System 7 (xe2x80x9cSS7xe2x80x9d) network. However, in a preferred embodiment, the S-SN has no actual voice trunks installed, i.e., does not emulate the full capabilities of an SSP. In a preferred embodiment, the computer control terminal is operated by a national or regional authority such as the National Weather Service (xe2x80x9cNWSxe2x80x9d).
In the present invention, an operator (or software) on the computer control terminal transmits a warning message to the S-SN along with the geographic regions to be warned. In a preferred embodiment, the computer control terminal is equipped with a graphical user interface allowing an operator to select the warning area by highlighting different portions of a map. The maps used in this preferred embodiment have a range of scales, down to the street-level, enabling highly specific targeting of the warning area.
In a preferred embodiment, the S-SN maintains a database of all customers having subscriptions to CND service, CNAM service or both. The database includes the subscribers"" telephone number and geographic location (e.g., a street address). In an alternate embodiment, the database stores information only for those customers specifically subscribing to the Disaster Warning service. The S-SN identifies the subscribers within the specific geographic region to be warned and initiates a series of telephone calls in rapid succession to all of the identified subscribers. The S-SN issues call setup messages in which the Calling Party Number (xe2x80x9cCgPNxe2x80x9d) field is set to a numeric code corresponding to the type of emergency. In this way, when a subscriber""s customer premises equipment (xe2x80x9cCPExe2x80x9d) displays the calling party""s number, it displays the special warning code. Each type of emergency or action required is assigned a unique numeric code. When the numeric code is displayed as the calling number, the subscriber is alerted to the disaster.
Subscribers having CNAM service receive a text message displaying a brief warning message. In a preferred embodiment, a text message and the numeric code for each Disaster_Type are stored in an existing name database used to support CNAM services. Such name databases are generally stored on a Service Control Point (xe2x80x9cSCPxe2x80x9d). In response to a CNAM query, the SCP returns the disaster text message for display on the subscriber""s CPE. The text display provides all the information necessary to alert the subscriber of the impending danger. In an alternate embodiment, the disaster text message is contained within the call setup message issued by the S-SN. In this embodiment, a database query is not necessary.
The S-SN follows each call setup message with a call release message. However, to allow sufficient time for the delivery of the calling number and/or calling name, the call release message is sent only after a pre-determined waiting period elapses. The pre-determined waiting period is at least as long as the name retrieval timer set within the switch, i.e., the timeout period for CND or CNAM services. In a preferred embodiment, the pre-determined waiting period is at least six seconds.
It is an object of the present invention to provide a disaster warning system that overcomes the above-cited problems. More specifically, it is an object of the present invention to provide a disaster warning system that is targeted to reach only people in imminent danger.
Another object of the present invention is to provide a disaster warning system that minimizes the incidence of false alarms.
Another object of the present invention is to provide a disaster warning system that is compatible with existing telecommunications equipment.
Another object of this invention is to provide a disaster warning system using telecommunications equipment that is already prevalent in people""s homes and/or workplaces.
Another object of the present invention is to provide a disaster warning system capable of reaching people in a targeted area almost simultaneously with the determination to issue the warning.